Rust-proofing material for metals



June 1, 1943. J. G. FORD 2,320,921

RUST-PROOFING MATERIAL FOR METALS Filed July 20, 1938 Cfi/or/krafd aramaf/c hydrocarbon fi/m.

WlTN ESSES:

INVENTOR Jbme: .Fora'.

Patented June 1, 1943 RUST-PROOFING MATERIAL FOR METALS James G. Ford, Forest Hills, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation oi Pennsylvania Application-July 20, 1938,'Serial No. 220,410

3 Claims.

The invention relates generally to rust-proofing materials for metal parts and more particularly to rust-proofing materials which are soluble in dielectric liquids.

Heretofor in rust-proofing the inside surfaces of metal containers provided for electrical apparatus which are operated in dielectrics, varnishes and other material have been employed which when subjected to oil as a dielectric were not attached and were therefore satisfactory but with the advent of fireproof dielectrics they were attacked and introduced quantities of deleterious matter, that was objectionable. This deleterious matter clogs circulating systems and sometimes renders the apparatus inoperative.-

The object of the present invention is to provide a rust-proofing material for application to the inside surfaces of containers utilized for holding chlorinated aromatic hydrocarbon dielectrics which will not introduce deleterious matter into the dielectrics.

It is also an object of the invention to provide a rust-proofing material for the inside surfaces of cases provided for electrical apparatus which will dissolve and disappear in the dielectrics in which the electrical apparatus is operated without changing its characteristics.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises a composition of matter possessing the characteristics, properties and the relation of components which will be exemplified in the composition hereinafter described and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing, in

which:

The single figure is a view in side elevation of a container for electrical apparatus, the inside of which is coated in accordance with this invention.

With the advent of aromatic hydrocarbon dielectrics, a rust-proofing material for the containers for electrical apparatus was demanded by the trade which on being dissolved in the dielectric would not form a sludge.

The present rust-proofing material in the preferred form comprises some suitable solid chlorinated aromatic hydrocarbon dissolved in a pe trbleum benzine to provide a solution of the proper viscosity for application to the containers in some well known manner, as, for example, the

flowing on of the material, dipping or spraying. The method of applying will to some extent dicmm the viscosity of the solution. Good results have been obtained by utilizing from 30% to 50% by weight of chlorinated aromatic hydrocarbon solids in a petroleum benzine solvent.

The chlorinated aromatic hydrocarbons that have given the most desirable results comprise one or more of the following: chlorinated diphenyl, chlorinated to contain from to 68% chlorine content, chlorinated diphenyl oxide with 60% to 68% chlorine content, chlorinated naphthalene containing at least 4 chlorine atoms; for example, tetrachlor-naphthalene and the higher chlomaphthalenes, and the chlorinated derivatives of diphenyl. Suitable solvents for these materials comprise at least one'of the aromatic hydrocarbons, such as benzene, toluene or xylene.

In practice, it has been found that a 40% solution of chlorinated diphenyl of resinous character, such as that sold under the trade name Aroclor #4465 or #5460 or a solution of chlorinated naphthalene marketed under the trade name Halowax #1003 or #1004 or a combination of, these two materials in solution in petroleum benzine or other suitable hydrocarbon solvent may readily be applied with excellent results.

When a material such as described hereinbefore has been applied to the surface of the metal container, it is air dried. Since this rust-proofing material may be applied and treated inthis inexpensive manner, it has been found very suitable for general application.

A rust-proofingmaterial of this type will prevent rust over a reasonable length of time. When the container is finally utilized in assembling electrical apparatus and a chlorinated aromatic hydrocarbon dielectric is introduced into the tank, the material is dissolved in'the dielectric. Since the rust-proofing material disclosed is of substantially the same general composition as the chlorinated aromatic hydrocarbon dielectrics now sold to the trade it becomes dissolved in the dielectric without in any way contaminating it or changing its electrical characteristics. 1 7

When oils are employed, they will dissolve the rust-proofing material without any objectionable results. Oxidation tests on oils which have dissolved the present rust-prooflng material show no appreciable physical change in the oil or decrease in its value as a dielectric.

It will be readily appreciated that other chlorinated hydrocarbon solids and other hydrocarbon solvents may be employed with success.

' Those listed appear to be sufficient to enable any one skilled in the art to make the proper selection from among the other aromatic hydrocarbons, which are so numerous that they all cannot be mentioned.

Since certain changes may be made in the above product and difl'erent embodiments of the invention can be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. The method of protecting a chlorinated aromatic dielectric employed in combination with electrical apparatus disposed in a ferrous container which comprises applying to the ferrous container a material comprising a solid chlorinated aromatic compound selected from the group consisting of chlorinated diphenyl, chlorinated naphthalene and chlorinated derivatives of diphenyl and a solvent for the solid chlorinated aromatic compound, the solvent comprising an aromatic hydrocarbon selected from the group consisting of benzene, toluene and xylene, the

materials being mixed in proportions to give a composition having a viscosity which facilitates the application to the container and which upon drying provides a protective coating.

2. The method of protecting a chlorinated aromatic dielectric employed in combination with electrical apparatus disposed in a ferrous container which comprises applying to the ferrous container a solid material comprising at least one of the chlorinated aromatic compounds selected from the group consisting of a chlorinated diphenyl containing from to by weight chlorine, chlorinated naphthalene chlorinated to contain at least four chlorine atoms, and a chlorinated derivative of diphenyl, and at least one of the aromatic hydrocarbon solvents selected from the group comprising benzene, toluene, and xylene, the solid chlorinated aromatic compound selected being soluble in the dielectric employed, the materials selected being mixed in the proper proportions to facilitate application to the container and dried after application to provide a.

protective coating whereby in the operation of the electrical apparatus no deleterious matter Will be introduced into the dielectric.

3. The method of protecting a chlorinated aromatic dielectric employed in combination with electrical apparatus disposed in a ferrous metal container which comprises applying to the ferrous metal container a material which consists of a solid chlorinated aromatic compound selected from the group consisting of chlorinated diphenyl, chlorinated naphthalene, and chlorinated derivatives of diphenyl and a solvent for the solid chlorinated aromatic compound, the solvent being selected from the group petroleum, benzine, toluene, benzene, and xylene, the selected solid chlorinated aromatic compound and solvent being mixed in proportions to give a product having a viscosity which facilitates application as a coating to the ferrous metal container, the solvent being volatile whereby it evaporates quickly leaving a protective residue which may be completely dissolved by the dielectric without collecting deleterious matter.

JAMES G. FORD. 

